Sail Chat Completions API API

openapi: 3.1.0
info:
  title: Sail Batches API Chat Completions API API
  version: '2026-02-18'
  description: Sail provides OpenAI-compatible Responses and Chat Completions endpoints, plus an Anthropic-compatible Messages endpoint. This reference documents the currently supported subset of fields.
servers:
- url: https://api.sailresearch.com/v1
security:
- BearerAuth: []
tags:
- name: Chat Completions API
  description: OpenAI-compatible Chat Completions API endpoints.
paths:
  /chat/completions:
    post:
      operationId: createChatCompletion
      tags:
      - Chat Completions API
      summary: Create a chat completion
      description: 'OpenAI-compatible Chat Completions endpoint. Supports streaming via stream: true, which returns a Server-Sent Events stream of chat.completion.chunk objects.'
      parameters:
      - $ref: '#/components/parameters/IdempotencyKey'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreateChatCompletionRequest'
            example:
              model: zai-org/GLM-5.2-FP8
              messages:
              - role: system
                content: You are a concise assistant.
              - role: user
                content: Summarize retrieval-augmented generation in 3 bullets.
              max_completion_tokens: 300
      responses:
        '200':
          description: 'Chat completion. Returns a single JSON object by default, or a Server-Sent Events stream of chat.completion.chunk objects when stream: true (terminated by a final data: [DONE] line).'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ChatCompletionResponse'
            text/event-stream:
              schema:
                $ref: '#/components/schemas/ChatCompletionChunk'
        '400':
          description: Invalid request or unsupported feature.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '401':
          description: Authentication error.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '408':
          description: Timed out waiting for completion.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '500':
          description: Server error.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
components:
  schemas:
    ChatCompletionChunkChoice:
      type: object
      required:
      - index
      - delta
      properties:
        index:
          type: integer
        delta:
          $ref: '#/components/schemas/ChatCompletionChunkDelta'
        logprobs:
          type: 'null'
        finish_reason:
          type:
          - string
          - 'null'
          enum:
          - stop
          - tool_calls
          - null
      additionalProperties: false
    RequestMetadata:
      type: object
      description: Optional string metadata. completion_window controls scheduling; completion_webhook/webhook_token configure completion webhooks.
      properties:
        completion_window:
          type: string
          description: '[Completion window](/completion-windows) (i.e. latency tier) for the request. Support matrix is available on the [Pricing](/pricing) page. When omitted, defaults to `standard` if that window is supported for the model; otherwise `flex` for async requests when the model supports it, and `asap` in all other cases. See [default behavior](/completion-windows#default-behavior).'
          enum:
          - asap
          - priority
          - standard
          - flex
        completion_webhook:
          type: string
          format: uri
        webhook_token:
          type: string
      additionalProperties:
        type: string
    ChatCompletionUsage:
      type: object
      required:
      - prompt_tokens
      - completion_tokens
      - total_tokens
      properties:
        prompt_tokens:
          type: integer
        completion_tokens:
          type: integer
        total_tokens:
          type: integer
        prompt_tokens_details:
          type: object
          additionalProperties: true
        completion_tokens_details:
          type: object
          additionalProperties: true
      additionalProperties: false
    CreateChatCompletionRequest:
      type: object
      required:
      - model
      - messages
      properties:
        model:
          type: string
        messages:
          type: array
          minItems: 1
          items:
            $ref: '#/components/schemas/ChatCompletionMessage'
        temperature:
          oneOf:
          - type: number
            minimum: 0
            maximum: 2
          - type: 'null'
        top_p:
          oneOf:
          - type: number
            minimum: 0
            maximum: 1
          - type: 'null'
        max_completion_tokens:
          oneOf:
          - type: integer
            minimum: 1
          - type: 'null'
        response_format:
          oneOf:
          - $ref: '#/components/schemas/ChatResponseFormatText'
          - $ref: '#/components/schemas/ChatResponseFormatJsonSchema'
        reasoning_effort:
          oneOf:
          - type: string
            enum:
            - none
            - minimal
            - low
            - medium
            - high
            - xhigh
          - type: 'null'
        n:
          type: integer
          enum:
          - 1
          description: Only n=1 is currently supported.
        modalities:
          type: array
          minItems: 1
          maxItems: 1
          items:
            type: string
            enum:
            - text
        stream:
          type: boolean
          description: When true, the response is returned as a Server-Sent Events stream of chat.completion.chunk objects instead of a single JSON response.
        stream_options:
          type: object
          description: Options that apply when stream is true.
          properties:
            include_usage:
              type: boolean
              description: When true, emit a final chunk with token usage for the full request before the [DONE] terminator.
          additionalProperties: false
        store:
          type: boolean
          enum:
          - true
          description: Only true is supported.
        user:
          type: string
          maxLength: 256
        metadata:
          $ref: '#/components/schemas/RequestMetadata'
      additionalProperties: true
    ChatResponseFormatText:
      type: object
      required:
      - type
      properties:
        type:
          type: string
          enum:
          - text
      additionalProperties: false
    ChatTextContentPart:
      type: object
      required:
      - type
      - text
      properties:
        type:
          type: string
          enum:
          - text
        text:
          type: string
      additionalProperties: false
    ErrorObject:
      type: object
      required:
      - message
      - type
      properties:
        message:
          type: string
        type:
          type: string
        param:
          oneOf:
          - type: string
          - type: 'null'
        code:
          oneOf:
          - type: string
          - type: integer
          - type: 'null'
      additionalProperties: true
    ChatCompletionChoice:
      type: object
      required:
      - index
      - message
      - logprobs
      - finish_reason
      properties:
        index:
          type: integer
        message:
          $ref: '#/components/schemas/ChatCompletionResponseMessage'
        logprobs:
          type: 'null'
        finish_reason:
          type: string
          enum:
          - stop
          - length
          - tool_calls
          - content_filter
          - function_call
      additionalProperties: false
    ChatCompletionChunkToolCall:
      type: object
      properties:
        index:
          type: integer
        id:
          type: string
        type:
          type: string
        function:
          $ref: '#/components/schemas/ChatCompletionChunkToolCallFunction'
        custom:
          $ref: '#/components/schemas/ChatCompletionChunkToolCallFunction'
      additionalProperties: false
    ChatCompletionResponse:
      type: object
      required:
      - id
      - object
      - created
      - model
      - choices
      properties:
        id:
          type: string
        object:
          type: string
          enum:
          - chat.completion
        created:
          type: integer
        model:
          type: string
        choices:
          type: array
          minItems: 1
          items:
            $ref: '#/components/schemas/ChatCompletionChoice'
        usage:
          $ref: '#/components/schemas/ChatCompletionUsage'
      additionalProperties: true
    ChatCompletionChunk:
      type: object
      description: 'One Server-Sent Events chunk emitted when stream: true. The streamed response is a sequence of these chat.completion.chunk objects, each sent as an SSE data: line and terminated by a final data: [DONE] line.'
      required:
      - id
      - object
      - created
      - model
      - choices
      properties:
        id:
          type: string
        object:
          type: string
          enum:
          - chat.completion.chunk
        created:
          type: integer
        model:
          type: string
        choices:
          type: array
          items:
            $ref: '#/components/schemas/ChatCompletionChunkChoice'
        usage:
          $ref: '#/components/schemas/ChatCompletionUsage'
      additionalProperties: false
    ChatCompletionResponseMessage:
      type: object
      required:
      - role
      - content
      properties:
        role:
          type: string
          enum:
          - assistant
        content:
          oneOf:
          - type: string
          - type: 'null'
        reasoning_content:
          oneOf:
          - type: string
          - type: 'null'
        refusal:
          oneOf:
          - type: string
          - type: 'null'
      additionalProperties: true
    ChatCompletionChunkToolCallFunction:
      type: object
      properties:
        name:
          type: string
        arguments:
          type: string
        input:
          type: string
      additionalProperties: false
    ChatCompletionMessage:
      type: object
      required:
      - role
      properties:
        role:
          type: string
          enum:
          - system
          - user
          - assistant
          - tool
          - function
          - developer
        content:
          oneOf:
          - type: string
          - type: 'null'
          - type: array
            items:
              oneOf:
              - $ref: '#/components/schemas/ChatTextContentPart'
              - $ref: '#/components/schemas/ChatImageContentPart'
        name:
          type: string
        tool_calls:
          type: array
          items:
            type: object
            additionalProperties: true
        tool_call_id:
          type: string
        function_call:
          type: object
          additionalProperties: true
      additionalProperties: false
    ChatResponseFormatJsonSchema:
      type: object
      required:
      - type
      - json_schema
      properties:
        type:
          type: string
          enum:
          - json_schema
        json_schema:
          type: object
          required:
          - name
          properties:
            name:
              type: string
            description:
              type: string
            schema:
              type: object
              additionalProperties: true
            strict:
              type: boolean
          additionalProperties: false
      additionalProperties: false
    ErrorResponse:
      type: object
      required:
      - error
      properties:
        error:
          $ref: '#/components/schemas/ErrorObject'
      additionalProperties: false
    ChatImageContentPart:
      type: object
      description: Image content part. Image input is supported only on multimodal models; see the Models page.
      required:
      - type
      - image_url
      properties:
        type:
          type: string
          enum:
          - image_url
        image_url:
          type: object
          required:
          - url
          properties:
            url:
              type: string
              description: Public http(s) URL or a base64 data URI.
            detail:
              type: string
              enum:
              - auto
              - low
              - high
          additionalProperties: false
      additionalProperties: false
    ChatCompletionChunkDelta:
      type: object
      properties:
        role:
          type: string
        content:
          type: string
        reasoning_content:
          type: string
        refusal:
          type: string
        tool_calls:
          type: array
          items:
            $ref: '#/components/schemas/ChatCompletionChunkToolCall'
      additionalProperties: false
  parameters:
    IdempotencyKey:
      name: Idempotency-Key
      in: header
      required: false
      schema:
        type: string
        maxLength: 255
      description: Makes the request retry-safe. Sail stores a reservation keyed by (organization, API key, Idempotency-Key); retrying with the same value returns the previously stored response instead of re-running inference. Keys are capped at 255 characters. See [Idempotent Requests](/idempotency) for full semantics.
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      bearerFormat: API Key